Les Paul hates my amp

[clyde1]

Is that what you think it is-lack of headroom? If I sub in a 20k resistor in tandem with the 18k after the screen supply, I get 340v B+ to the CF (pin 6), and 241v and 235v on the PI plates. I have a 3.9k after the PI to the CF. Would making that one smaller be better as far as the PI is concerned?